What is IP Masquerading?

“MASQ” or “IPMASQ”, short for IP Masquerading, helps machines with non-routable IP addresses to access Internet via the machine that is actually masquerading. It is a form of NAT (Network Address Translation). IPMASQ works perfectly with LAN technologies like Token Ring, Ethernet, FDDI and dial-up connections.

In case of IPMASQ a gateway machine acts as the mediator between the machines on your network and the Internet. Connection Tracking (conntrack) feature of Linux is used to keep track of connections and their source. This helps in rerouting the packets accordingly. Henceforth, packets leaving the private network are masqueraded as if they originated from the mediator machine. Microsoft calls this feature as Internet Connection Sharing.